1. Technical Field
The present invention relates to a technology of pressurizing and depressurizing in which a pressurizing process of pressurizing liquid, and a depressurizing process of depressurizing liquid are performed in a liquid ejecting apparatus which ejects liquid such as ink from nozzles of a print head.
2. Related Art
In the related art, a liquid ejecting apparatus such as a printer which ejects liquid such as ink from nozzles of a print head has been known. In such an apparatus, there is a case in which ejecting of liquid is not appropriately performed due to bubbles in liquid, and for example, a quality of printing using liquid deteriorates. Therefore, for example, in an apparatus disclosed in JP-A-2010-208186, a depressurizing pump is operated after ending a printing operation, and deaeration processing is executed by pressurizing liquid (depressurizing process).
In addition, since it is not possible to perform good liquid ejection when bubbles or foreign substances are mixed into nozzles, for example, a printing quality deteriorates. Therefore, in an apparatus disclosed in JP-A-2010-255538, bubbles are discharged from nozzles by pressurizing ink in an ink supply tube using a pressurizing pump (pressurizing process).
In order to perform high quality printing, it is desirable to perform the above described pressurizing process and depressurizing process. In order to perform these processes, it is necessary to operate a pressurizing pump in every pressurizing process by operating the pressurizing pump in every depressurizing process. However, a value of a positive pressure or a negative pressure which is applied from the pump is unstable immediately after starting the operation of the pump. In addition, there is a case in which it is difficult to preferably perform pressurizing and depressurizing, when the operation of the pump is limited due to an operational condition of an apparatus, or the like.